FRI051 Lean Mass And Fat Mass Across Different Age Groups In The Thai Population

Disclosure: N. Charoenngam: None. D. Theerakulpisut: None. D. Sribenjalak: None. C. Pongchaiyakul: None. Introduction: Lean mass and fat mass have been shown to influence the risks of cardio-metabolic disorders. While obesity is defined as body mass index (BMI) of more than 30 kg/m(2) in White, Hispanic, and Black individuals and 25 kg/m(2) in Asian individuals, the cut-off values for lean mass and fat mass in different populations are less well-defined as data on reference values of lean mass (LM) and fat mass (FM), especially in the Southeast Asians, are limited. In this study, we aimed to determine the normative values of LM and FM across different age groups in the Thai population. Methods: Male and female consecutive community-dwelling individuals aged 20 - 90 years were recruited from Srinagarind Hospital, Khon Kaen, Thailand between 2010 and 2015. LM and FM were measured using dual energy x-ray absorptiometry on a Lunar Prodigy bone densitometer (GE Healthcare, Madison, WI). Lean mass index (LMI) and fat mass index (FMI) were calculated [LMI = LM (kg)/height (m)(2), FMI = FM (kg)/height (m)(2)]. Percentiles of each variable stratified by age and sex were calculated. SPSS version 27 (SPSS Inc., Chicago, IL) was used to perform statistical analysis. Results: A total of 832 individuals (334 males and 498 females) were included in the study. The mean ± SD age, LM, FM, LMI and FMI were 50.0 ± 16.2 years, 38.9 ± 8.0 kg, 15.5 ± 7.7 kg, 15.6 ± 2.3 kg/m(2) and 6.4 ± 3.3 kg/m(2), respectively. In males, the median LM decreased from with age from 49.4 kg in 20 - 29 years group to 42.3 kg in ≥70 years group. The median LMI was relatively unchanged from age 20 - 59 years at 17.7 - 18.0 kg/m(2) and dropped to 16.4 kg/m(2) in ≥70 years group. The median FM and FMI increased with age from 6.3 kg and 2.5 kg/m(2) in 20 - 29 years group to 11.9 kg and 4.6 kg/m(2) in 60 - 69 years group and dropped to 10.3 kg and 4.1 kg/m(2) in ≥70 years group. In females, the median LM peaked at age 30 - 39 years at 34.6 kg and decreased with age to 30.8 kg in ≥70 years group. The median LMI peaked at age 40 - 49 years at 14.6 kg/m(2) and decreased with age to 13.8 kg/m(2) in ≥70 years group. The median FM and FMI peaked at age 50 - 59 years at 20.7 kg and 9.0 kg/m(2) and decreased with age to 15.9 kg and 7.1 kg/m(2) in ≥70 years group. Conclusion: We generated age-stratified normative values of LM, FM, LMI and FMI from the cross-sectional data of community-dwelling Thai individuals. We observed that LM achieved its peak during early adulthood (age 20 - 29 years in males and 30 - 39 years in females) and decreased with older age. On the other hand, an inverse-U shaped association between FM and age was observed as FM achieved its peak at age 60 - 69 years in males and 50 - 59 in females and decreased with older age. Presentation: Friday, June 16, 2023